This invention relates generally to packaging and to flexible packaging. More particularly, this invention relates to packages made from flexible packaging material having an opening sealed by a peelable seal that may be hand opened.
Flexible containers or packages formed of sheet materials have been used for many years and have wide acceptance for holding various air-perishable products, e.g., coffee and other foodstuffs. Prior art flexible, air-tight packages are commonly constructed of some plastic film, metal foil, or combinations thereof, in one or more plies and sealed along one or more seams. Such packages are usually vacuumized after filling but prior to sealing so that the contents of the package are not exposed to the degradation effects of air. Accordingly, products held in such packages can have a shelf life comparable to rigid packages, such as jars with screw-on lids or metal cans.
The advantages of flexible packages over rigid packages are many. For example, flexible packages can be manufactured at substantially lower cost and can be stored flat, thereby resulting in enormous space savings over rigid packages. Moreover, flexible packages are substantially lighter in weight, thereby resulting in reduced transportation costs for unfilled packages. Further still, flexible packages are generally of an overall parallelepiped shape when filled so that such packages take up considerably less shelf or storage space. Needless to say, this feature is of considerable importance insofar as transportation, storage, and display are concerned.
It is common practice to construct the package or bag by heat sealing laminated material to form the package. The package is then filled and its opening typically heat sealed closed to produce the final product for shipment. Packages of the above description may be used in vacuum packing, a familiar technique in which the contents are exposed to a reduced atmosphere during the sealing operation to draw off air or to eliminate gasses which otherwise might evolve or diffuse out of products over time. The present invention may be used, to equal advantage, with vacuum, non-vacuum, or gas-flushed packages.
The seals for packages of the above-described type must of course be strong enough to withstand routine handling and foreseeable mishandling, and to avoid spillage due to failure of the closure. Also, the closure must be strong enough and permanent enough to resist tampering. In typical prior art packages, the seals are often as strong as the other seams of the package. Opening may require the use of knives, scissors or other cutting instruments. As an alternative, schemes have been proposed for the use of frangible elements, tear strips or drawstrings, to facilitate opening. Each of these in some measure complicates the production process, and results in partial or complete destruction of the package upon opening. This latter attribute is itself undesirable, for in the marketing of certain products, it is common to open the package, process the contents (as, for example, in the grinding of coffee beans), and return the processed contents to the package.
While prior art air-tight, flexible packages exhibit the aforementioned advantages over rigid packages, there are still some undesirable characteristics, particularly when it is desired to be able to open and reclose the package after its initial opening. In this regard, as indicated above, the seams of prior art flexible packages are usually permanent in the interest of air tightness and structural integrity and are commonly formed by conventional heat sealing or welding techniques. Thus, the prior art flexible package is typically opened by cutting or tearing one or more of its seams.
Additionally, in the prior art, there is a plastic bag with a peelable portion to form a spout disclosed in U.S. Pat. No. 4,953,708 to Beer. There are many other examples of packages with peelable seal openings, both patented and commercially available. Easy access to a granular product packaged in a flexible material can be provided as described in U.S. Pat. No. 4,518,087 to Goglio.
Another flexible package is disclosed in U.S. Pat. No. 4,488,647 to Davis. Here, the peal seal is not provided in a pattern, but is continuous around the upper end portion of the package such that the adhesive extends into the heat sealed seams, thereby reducing the structural integrity of the package.
Generally, the prior art discloses methods of gaining entry to a package. But, there is no concern that the opening would extend into a sealed corner.
The present invention provides a flexible package which features an easy opening peel seal which can be manufactured in a variety of strengths, and which, unlike known previously existing peel seals is sufficiently strong to meet all of the usual requirements, including the ability to reliably retain vacuum. Another aspect of the novel peel seal of the present package is extreme simplicity of manufacture, in which the making of the seal lends itself to continuous processes of the kinds used to make and fill packages.
Importantly, the area of the peel seal of the present invention does not interfere with the other permanent seams of the package. The process of applying a coating to predetermined area of a laminate web is generally referred to in the flexible packaging industry as "pattern coating". The peel seal is placed on the laminated material by the "pattern coating" wherein the peal seal adhesive is placed away from the heat sealed seams and placed in a pattern only on that portion of the laminate that is actually pealed opened. Therefore, the structural integrity of the main seams is maintained.